EHV in Wisconsin: Only One Farm Affected, Report Says

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Thanks to the Wisconsin State Horse Council and Wisconsin Equine Clinic for the following information on an occurence of Equine Herpes Virus, Type 1, in the state of Wisconsin. Please note that the farm is not named, nor is the breed of horse specified. The update is provided by Scott Austin, DVM, Diplomate ACVIM, of the Wisconsin Equine Clinic:

(begin quote from report)

The current outbreak is confined to a single farm (to my knowledge, I haven't been able to track down all the rumors) located in Jefferson County.

The index case (Horse A) was diagnosed with EHV-1 infection on January 22 based on a positive PCR (polymerase chain reaction) test of both a nasal swab and blood. At that time a voluntary quarantine of the farm was put into effect and twice daily temperature manitoring was instituted.

On January 23 the EHV-1 was confirmed as the neurotropic form of the virus. All resident horses were tested for EHV-1 by PCR testing of a nasal swab and blood. On the day of testing, 3 horses were identified as having fevers (horses B, C, & D). No horses were positive on nasal swabs for EHV-1 and 1 horse was positive on the blood test (Horse B).

The current status of horses on the property is as follows:

* Horse A: index case, confirmed positive for neurotropic EHV-1. He developed rear limb paralysis and went down. This horse was euthanized 4 days after the diagnosis was made.
* Horse B: Fever and positive PCR on blood. Fever has resolved and no other clinical signs have been seen.
* Horse C: Fever and negative PCR on blood and nasal swab. This horse developed rear limb ataxia and bladder paralysis on day 3 after testing. He became recumbent within 12 hours and was euthanized. A PCR on his blood at the time of euthanasia was still negative for virus. Results of post-mortem examination are still pending.
* Horse D: Fever and negative PCR on blood and nasal swab. The fever resoloved within 36 hours and no clinical signs of respiratory or neurological disease have been seen.

The voluntary quarantine on the farm remains in effect. No new febrile horses or clinical signs of respiratory or neurolgical disease have been identified since January 27, 2007."

end quote from report

Note to blog readers: This report gives you a good idea of the "lingo" used to describe horses with medical and neurological symptoms of disease. It is not known if these horses were racehorses, show horses, or pleasure horses.